I live in the New York Metro Area where winter temperatures can get down to single digits fahrenheit . My commute is 27 miles each way with a 50 /50 split between highway and back roads. In warmer months, where I do not use any climate control, I can average between 215 - 240 watts per mile. In the winter, I am seeing 240 - 300+ watts per mile with very conservative heat usage. I always per-condition my car at home using a hard wired Levition L2 charger.
For the past 15 months, I was able to charge at work using the Level 1 charger and could generally charge to 100% before heading home. Unfortunately my office building has changed their policy of allowing me to charge (for free or even paid) with the growth of more electric vehicles in the parking lot. (Mostly Teslas but even a few Ford Fusion Plug-In hybirds). It is still questionable, but building may install Level 2 chargers in the future which would be fantastic.
For now, I am left with either putting on full ski gear just to go to work during the cold winter months, or come up with an alternative method to heat the cabin safely without cutting into my car's battery and driving range.
I was able to get a hold of a few three year old UPS 70AH 12V AGM deep cycle batteries for free that were in good shape. I first investigated using electric resistive golf cart heaters and stringing them in series to give 36vdc or 48vdc. The cost for the heater that would put out about 5000 btu (drawing around 1.5kw) was just over $200. I would also need a battery charger. The 36v or 48v battery chargers seemed to be in the range of $250 - $350. A 12v 40ah - 100ah charger was around $130 - $200 but this would require more wired connections to allow charging in parallel.
I ultimately decided to go with a marine grade 12v inverter / charger capable of proving 1.8kw of continuous power and could charge at 40ah and trickle at 2ah. This would also allow me to use it during the summer on my boat or possibly just hard wire it in the future to a few circuits in my house in case of a power outage. For heat, purchased a small ceramic space heater that could draw either 900w or 1500w. Batteries would be hooked up in parallel to provide a total of 280ah at 12v (using 4 70ah deep cycle batteries). I would use short runs of 1/0 wire to connect the batteries.
Yesterday I got all the parts I would need to do a preliminary hookup and test before trying to mount it in the car. It was late so I only ran the heater on the inverter for about 10 minutes. So far it all lookes good and the wires and terminals interconnecting the batteries and to the inverter did not heat up.
Tonight I plan to do a longer test to see if I can get about 20-30 minutes at 1500 watts and another 30+ minutes at 900 watts without totally depleting the batteries. I will report back my results soon. Hopefully once I get the heater in the car on a cold day (below 20F) I can figure out how much time I can realistically run at 900 watts and still be comfortable.
Still up in the air is where I would store the batteries in the car. Each battery weighs 60bs so I am looking at 240lbs. Initially I thought of putting them in the lower trunk area (removing the insert that makes the trunk area flat, but the total weight does make the car sag a bit. Ideally, the best place seems to be putting all four batteries on the floor of the back seating area for best weight distribution. I'm just concerned that it would render the back seat useless for any passengers (even for little ones).
Would be interested to hear any of your thoughts or answer any questions you might have on this setup.
For the past 15 months, I was able to charge at work using the Level 1 charger and could generally charge to 100% before heading home. Unfortunately my office building has changed their policy of allowing me to charge (for free or even paid) with the growth of more electric vehicles in the parking lot. (Mostly Teslas but even a few Ford Fusion Plug-In hybirds). It is still questionable, but building may install Level 2 chargers in the future which would be fantastic.
For now, I am left with either putting on full ski gear just to go to work during the cold winter months, or come up with an alternative method to heat the cabin safely without cutting into my car's battery and driving range.
I was able to get a hold of a few three year old UPS 70AH 12V AGM deep cycle batteries for free that were in good shape. I first investigated using electric resistive golf cart heaters and stringing them in series to give 36vdc or 48vdc. The cost for the heater that would put out about 5000 btu (drawing around 1.5kw) was just over $200. I would also need a battery charger. The 36v or 48v battery chargers seemed to be in the range of $250 - $350. A 12v 40ah - 100ah charger was around $130 - $200 but this would require more wired connections to allow charging in parallel.
I ultimately decided to go with a marine grade 12v inverter / charger capable of proving 1.8kw of continuous power and could charge at 40ah and trickle at 2ah. This would also allow me to use it during the summer on my boat or possibly just hard wire it in the future to a few circuits in my house in case of a power outage. For heat, purchased a small ceramic space heater that could draw either 900w or 1500w. Batteries would be hooked up in parallel to provide a total of 280ah at 12v (using 4 70ah deep cycle batteries). I would use short runs of 1/0 wire to connect the batteries.
Yesterday I got all the parts I would need to do a preliminary hookup and test before trying to mount it in the car. It was late so I only ran the heater on the inverter for about 10 minutes. So far it all lookes good and the wires and terminals interconnecting the batteries and to the inverter did not heat up.
Tonight I plan to do a longer test to see if I can get about 20-30 minutes at 1500 watts and another 30+ minutes at 900 watts without totally depleting the batteries. I will report back my results soon. Hopefully once I get the heater in the car on a cold day (below 20F) I can figure out how much time I can realistically run at 900 watts and still be comfortable.
Still up in the air is where I would store the batteries in the car. Each battery weighs 60bs so I am looking at 240lbs. Initially I thought of putting them in the lower trunk area (removing the insert that makes the trunk area flat, but the total weight does make the car sag a bit. Ideally, the best place seems to be putting all four batteries on the floor of the back seating area for best weight distribution. I'm just concerned that it would render the back seat useless for any passengers (even for little ones).
Would be interested to hear any of your thoughts or answer any questions you might have on this setup.
